Sound-reproducing device



Nov. 19, 1929. L. DE FOREST LVBQWS SOUND REPRODUCING DEVICE Filed Oct. 31. 1925 lNVEly TOR. m $2 5PM TTORN S.

Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE LEE 1)] FOB E5101 NEW YORK, N. Y. ASSIGNOR, BY MESN E ASSIGNMENTS, TO GENERAL TALKING PICTURES CORPORATION, A CORPORATION OF DELAWARE SOUND-REPBODUCING DEVICE.

Application filed October 81, 1925. Serial No. 65,916.

vision of a sound reproducing device having a vibrating membrane which is unattached at any point.

A further object of the invention is the production of a loud speaker device having a curved membrane but which is not of a circu lar configuration.

A still further object of the invention is the provision of a supporting framework for the curved membrane of this type, which is not rigidly secured to the supporting framework at any point.

One of the advantages of this invention is the self-adjustability of the vibrating membrane to any atmospheric changes of temperature or moisture.

These and other objects will appear as the description of my invention goes forward.

The novel features of this invention reside substantially in the construction, combination, arrangement and relative location of parts, as will be more fully described hereinafter.

.Referring to the drawings, in which the same reference numerals refer to the same elements throughout the several views,-

Fig. 1 is a rear elevational view of my novel sound reproducing device. I,

Fig. 2 is a front elevational view of my invention.

Fig. 3 is a cross-sectional view taken on the line 2;3 of Fig. 2, looking in the direction of the arrows.

Fig.4.i'sa view partly in section and partly in elevation showing t e motor mounted on the frameworkand the method of attaching it to the vibrating membrane.

My present invention is directed to the commercial form of structure embodying the basic principles contained in.my copending application, Serial No. 2,548, filed January 15, 1925; and it is to the structural features and advantages obtained thereby in the practical commercial adaptation of my prior. application that the present case is directed.

Referring to Fig. 1, the supporting framework is shown made up of three horseshoe shaped rings 1, 2 and 3, disposed horizontally upon a vertical framework 4. The two end rings 1 and 3 mounted at the ends of the fram 4 act as cap members for the membrane 5 which is disposed between these end members and within all three rings 1, 2 and3. Membrane 5 is freely disposed within this framework, and is unattached at any point.

Wherever it comes in contact with the sup-. porting framework small pieces of felt 6 are interposed between it and the support which are cemented to the support. Arranged within the membrane and mounted on the vertical frame 4 is a motor and its casing 7, which motor is of the well-known balanced armature type.

Projecting from the side of the motor is a spring arm 8 having a short rod member 9 attached thereto. Upon the membrane 5, ad-

jacent thejrod member 9 is a small plate 10 rigidly secured thereto. A small set screw device 11 is attached to this plate 10 in such a manner that the arm 8 projects into it and is rigidly secured thereto by means of a set screw. On the top of the motor casing 7 are mounted two binding posts 12, which are connected to the coils of the motor in the usual manner. The bottom ring v3 has projecting therefrom a plurality of cushion projections 3* which serve as feet for supporting the device on ahorizontal surface.

It will be evident by this description that I have produced a new and novel sound reproducing device in which there is provided a freely disposed vibrating membrane unattached at any point and to which the motor means is applied tangentially.

I am of course aware that my inventive concept may assume many modifications and forms, and I do not, therefore, desire to be limited to the particular embodiment of my inventive concept which I have shown in illustration and described herein; but rather by the spirit and scope of the claims appended hereto by means of which I have defined my invention.

What I claim, therefore, as new and useful, and dgsire to secure by Letters Patent is:

lJIn a sound reproducing device, a support, a curved diaphragm freely mounted in said support, and means for vibrating said diaphragm, said means being attached substantially tangentially to said diaphragm near its marginal edge. 7

2. In a sound reproducing device. a curved supporting framework, a curved diaphragm mounted in said framework so as to be floating without rigid attachment thereto but confined thereby, and actuating means for vibrating said diaphragm.

33111 a sound reproducing device, a sup porting fran'iework, a curved diaphragm mounted in said framework so as to be floating without rigid attachment thereto, and means for vibrating said diaphragm, said means being attached substantially tangentially to said diaphragm near its marginal edge.

4. In a sound reproducing device, an open supporting framework, a freely supported diaphragm within said framework and means for vibrating said diaphragm mounted within said framework, said vibrating means being applied substantially tangentially to said diaphragm.

5. In a sound reproducing device, an open framework comprising a plurality of ring shaped members, a flat member supporting said rings, a diaphragm in said framework, and means for vibrating said diaphragm.j

6. In a sound reproducing device, an open framework comprising a plurality of ring shaped members, a flat member supporting said rings, a diaphragm in said framework, means for vibrating said diaphragm, said means being mounted within and on said framework.

7 In a sound reproducing device, an open framework comprising a plurality of ring shaped members, a flat member supporting said rings, a curved diaphragm in said framework, and means for vibrating said' diaphragm.

8. In a sound reproducing device, an open framework comprising a plurality of ring shaped members, a flat member supporting said rings, a curved diaphragm in said framework, means for vibrating said dia hragm, said means being mounted within an on'said framework.

9. In a sound reproducing device, an open framework comprising a plurality. of ring sha ed members, a flat member supporting sai rings, a diaphragm in saidframework',

means for vibrating said diaphragm, said means being mounted within and on said framework, and attached substantially tangentially to said diaphragm.

10. In a sound reproducing device, an open framework comprising a'plurality of ring shaped members, a flat member supporting said rings, a diaphragm in said framework, and means for vibrating said diaphragm, said means being attached substantially tangentially to said diaphragm.

11. In a sound reproducing device, an open framework comprising a plurality of ring shaped members, a flat member supporting said rings, a curved diaphragm in said framework, and means for vibrating said diaphragm, said means being mounted within and on said framework, and attached substantially tangentially to said diaphragm.

1:2. In a sound reproducing device, an open supporting framework, a curved diaphragm freely supported in said framework, resilient means between said framework and said diaphragm, and means for vibrating said diaphragm attached substantially tangentially thereto.

In testimony whereof I have hereunto set my hand on this 26th day of October, A. D.

LEE on FOREST. 

